info.pppc.base.plugin.security.io

Class SecureOutputStream

java.lang.Object

java.io.OutputStream

java.io.FilterOutputStream

info.pppc.base.plugin.security.io.SecureOutputStream

All Implemented Interfaces:

java.io.Closeable, java.io.Flushable, java.lang.AutoCloseable

public class SecureOutputStream
extends java.io.FilterOutputStream

An AESOutputStream that encrypts and signs a byte stream using the AES algorithm and an HMAC with the SHA1-Hash-Algorithm. Please note that you should use two different keys for signing and for encryption!

Author:

WA

Field Summary

Fields

Modifier and Type	Field and Description
static short	MAXIMUM_DATA_BUFFER_SIZE

Constructor Summary

Constructors

Constructor and Description
SecureOutputStream(java.io.OutputStream out, AESSymmetricKey key, HMACSymmetricKey signKey, byte[] iv) Creates a new AESOutputStream that encrypts the given OutputStream with the given key and additionally signs it with the signature key.

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Closes the stream, first does a flush().
void	flush() Flushes the stream, creates a signature, if necessary.
void	write(byte[] b) Write a byte array completely.
void	write(byte[] b, int off, int len) Writes b bytes to the stream.
void	write(int b) Writes a single byte.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MAXIMUM_DATA_BUFFER_SIZE

public static final short MAXIMUM_DATA_BUFFER_SIZE

See Also:

Constant Field Values

Constructor Detail

SecureOutputStream

public SecureOutputStream(java.io.OutputStream out,
                  AESSymmetricKey key,
                  HMACSymmetricKey signKey,
                  byte[] iv)

Creates a new AESOutputStream that encrypts the given OutputStream with the given key and additionally signs it with the signature key. The signature key must not be identical to the AES key!

Parameters:

out - The OutputStream that should be encrypted (and signed)

key - The AES key that should be used for encryption

signKey - The symmetric key that is used to create the HMAC (signature)

iv - The initialization vector that is used to initialize the encryption

Method Detail

write

public void write(byte[] b)
           throws java.io.IOException

Write a byte array completely.

Overrides:

write in class java.io.FilterOutputStream

Parameters:

b - The byte array to write.

Throws:

java.io.IOException - Thrown by the underlying stream.

write

public void write(int b)
           throws java.io.IOException

Writes a single byte.

Overrides:

write in class java.io.FilterOutputStream

Parameters:

b - The byte to write.

Throws:

java.io.IOException - Thrown by the underlying stream.

write

public void write(byte[] b,
         int off,
         int len)
           throws java.io.IOException

Writes b bytes to the stream.

Overrides:

write in class java.io.FilterOutputStream

Parameters:

b - The buffer of data to write

off - The offset in buffer

len - The length of the data in the buffer

Throws:

java.io.IOException - Thrown by the underlying stream.

flush

public void flush()
           throws java.io.IOException

Flushes the stream, creates a signature, if necessary.

Specified by:

flush in interface java.io.Flushable

Overrides:

flush in class java.io.FilterOutputStream

Throws:

java.io.IOException - Thrown by the underlying stream.

close

public void close()
           throws java.io.IOException

Closes the stream, first does a flush().

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Overrides:

close in class java.io.FilterOutputStream

Throws:

java.io.IOException - Thrown by the underlying stream.